Refinishing headstock

Hey guys, quick question. I'm gonna sand my headstock and refinish it on my Squier strat, so at this point, my understanding is that I'll just remove the tuners and string trees, and sand it down starting with 50 grit, to 100, to 150. Then I'll... oil it I guess. So I have three questions. First, should I have to remove my nut to do this, or will I be okay just taping everything off? Second when I have sanded the face of the headstock down, so that it is raw wood, if I write something in thick Sharpie marker, and then proceed to oil it, will the Sharpie stay there? Third, what type of oil should I use? I was thinking tung oil, but only because that's pretty much the only one I'm familiar with. Thanks in advance.

I guess I'll go with tung oil then, seems easiest and simplest. Any advice on how many coats to put? And how should I apply it? I remember in shop class when we oiled stuff we would always rub it on, and then rub it off. Should that work?